Bicycle frame



FIG. 1 is an top and front perspective view of a bicycle frame showing my design.

FIG. 2 is an end view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a side view thereof;

FIG. 5 is an opposite side view thereof;

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a top plan view thereof. 

I claim the ornamental design for a bicycle frame, as shown and described. 